Question

What is the perimeter of a sector of angle 45 degrees of a circle with raidus 7 cm

Answer 1

Answer:

Perimeter of sector = 19.5 cm

Step-by-step explanation:

Radius = r = 7cm

Angle of sector = 45

Circumference of circle = 2*π*r

= 2*π*7

= 14π

Length of arc formed by sector of angle 45 = Circumference*(45/360)

= 14π*(45/360)

= 14π*(1/8)

= (7π)/4

Perimeter of the sector = Radius + Radius + Length of arc

                                        = 7 + 7 + (7π)/4

                                        = 14 + [(7π)/4]

                                         = (56 + 7π)/4

On using π = 22/7, we get:

Perimeter of sector = (56 + 22)/4

                                 = 78/4

                                 =  19.5

Perimeter of sector = 19.5 cm